JP2019025971A - Body lower part structure of vehicle - Google Patents

Abstract

To suppress vibrations of a floor panel 30 caused by transmission of vibrations from front wheels to a side sill 22 through a torque box 60 as much as possible, without deteriorating roll rigidity and the like of a vehicle body.SOLUTION: A plurality of torque boxes 60, which connect floor flames 21 to side sills 22, have a first torque box 61 and a second torque box 62 arranged to separate toward a rear side of a vehicle with respect to the first torque box 61. A protrusion quantity H3 of the first torque box 61 toward a floor panel 30 is smaller than a protrusion quantity H2 of the floor frame 21 toward the floor panel 30 in a position in a longitudinal direction of the vehicle corresponding to a connection part between the floor panel 21 and the first torque box 61.SELECTED DRAWING: Figure 5

Description

  The present invention belongs to a technical field related to a lower body structure of a vehicle.

  Conventionally, a pair of left and right side sills extending in the vehicle front-rear direction, a pair of left and right frame members positioned on the inner side in the vehicle width direction than the pair of left and right side sills and extending in the vehicle front-rear direction, the pair of left and right frame members, 2. Description of the Related Art A lower vehicle body structure of a vehicle is known that includes a torque box that connects a side sill closer to a frame member in the vehicle width direction.

  For example, in the lower body structure of a vehicle described in Patent Document 1, a side sill has a side sill extending in the front-rear direction, and an extension part on the rear side of the front side frame, and extends along the dashboard lower panel in the vehicle width direction. An extension portion that is inclined to the outside of the side sill inner and is coupled to the side wall of the front end portion of the side sill inner; A tunnel frame (frame member) extending to the floor, a floor panel coupled to the side sill inner and the tunnel frame, and an X-shaped core material in plan view comprising the first and second core materials, the first core The material extends obliquely toward the center of the vehicle width direction toward the rear side of the vehicle and connects the extension portion and the tunnel frame, and the second core material extends in the vehicle width direction toward the vehicle rear side. It extends outwardly inclined and couples the side sill inner and the tunnel frame.

  In the lower body structure of the vehicle described in Patent Document 1, the extension portion, the first core member, and the second core member function as a torque box.

  Moreover, in the lower vehicle body structure of the vehicle described in Patent Document 1, the protruding amount of the torque box with respect to the floor panel is the same as the protruding amount of the frame member with respect to the floor panel.

JP2013-103650A

  By the way, when the vehicle travels, vibrations from the left and right front wheels are transmitted to the floor panel, and the floor panel may vibrate. Specifically, the vibration of each front wheel is transmitted to the frame member from a suspension arm or the like that supports the front wheel, the frame member vibrates, the vibration of the frame member also vibrates the torque box, and the vibration of the torque box Causes the side sill to vibrate, and the vibration of the side sill causes the floor panel to vibrate. The vibration transmitted from the front wheels to the floor panel is attenuated by deforming the frame members and panels. However, if the rigidity of the frame members and panels is high, deformation is unlikely to occur and the vibration is not attenuated. Eventually it will be transmitted to the floor panel.

  In addition, the vibration of the floor panel as described above causes unpleasantness to the vehicle occupant and causes noise by vibrating the air in the passenger compartment. Harshness) problem becomes prominent.

  By reducing the size of the torque box and relatively reducing the vibration of the torque box, it is possible to reduce the vibration transmitted to the side sill via the torque box and suppress the vibration of the floor panel. If the size of the torque box is reduced, the roll rigidity of the vehicle body and the rigidity against the front impact may be reduced.

  In the lower body structure of a vehicle as described in Patent Document 1, a plurality of torque boxes are provided, and even if the size of one torque box is reduced, a reduction in rigidity with respect to a front collision can be suppressed to some extent. However, in the lower vehicle body structure of Patent Document 1, since the protrusion amount of the torque box with respect to the floor panel is the same as the protrusion amount of the frame member with respect to the floor panel, the ridge line of the frame member and the ridge line of the torque box are matched. The rigidity of the torque box becomes too high, and the torque box may transmit the vibration from the lower wall portion of the frame member to the side sill as it is. For this reason, in the lower vehicle body structure of the vehicle as described in Patent Document 1, vibration from the front wheels is easily transmitted to the floor panel even though the torque box is divided into a plurality of front and rear parts.

  The present invention has been made in view of such points, and an object of the present invention is to provide a floor panel resulting from the vibration of the front wheels being transmitted to the torque box without reducing the roll rigidity or the like of the vehicle body. It is to suppress the vibration of the as much as possible.

  In order to solve the above-described problems, the present invention is directed to a lower body structure of a vehicle, and a pair of left and right floor frames that extend in the vehicle front-rear direction and are attached to the lower surface of the floor panel; A pair of left and right side sills attached to the outer ends in the vehicle width direction, a suspension cross member that connects the front end portions of the left and right floor frames and supports the left and right front wheel suspension arms, and the left and right sides of the vehicle Provided with a plurality of torque boxes that connect the left and right pair of floor frames and the pair of left and right side sills at the left and right sides, respectively, the plurality of torque boxes at the left and right sides of the vehicle, The first torque box and the rear side of the vehicle with respect to the first torque box The floor frame has a U-shaped cross section that opens upward and forms a closed cross section in cooperation with the floor panel. The first and second torque boxes have a U-shaped cross section that opens upward in the vehicle longitudinal direction, and each has a closed cross section in cooperation with the floor panel. The amount of protrusion of the torque box with respect to the floor panel is equal to or less than the amount of protrusion of the floor frame with respect to the floor panel at the same vehicle front-rear position as the connecting portion between the floor frame and the second torque box. The amount of protrusion of the torque box with respect to the floor panel is the same as that of the connecting portion between the floor frame and the first torque box at the front and rear positions of the vehicle. Smaller than the projection amount for the floor panel of the floor frame, has a structure that.

  According to this configuration, since the floor frame is coupled to the suspension cross member that supports the front wheel suspension arm, the vibration from the front wheel is transmitted to the floor frame via the front wheel suspension arm and the suspension cross member.

  At this time, if the amount of protrusion of the first torque box with respect to the floor panel is the same as the amount of protrusion of the floor frame with respect to the floor panel at the same vehicle front-rear position as the connecting portion between the floor frame and the first torque box. The ridgeline of the floor frame and the ridgeline of the first torque box coincide with each other, the rigidity of the first torque box becomes too high, and the vibration from the lower wall portion of the floor frame is directly transmitted to the side sill. End up.

  Therefore, in the present invention, the protrusion amount of the first torque box with respect to the floor panel is made smaller than the protrusion amount of the floor frame with respect to the floor panel at the same vehicle front-rear position as the connecting portion between the floor frame and the first torque box. As a result, the rigidity of the first torque box is lower than the case where the ridge line of the floor frame and the ridge line of the first torque box coincide with each other. Therefore, the first torque box is easily deformed by the vibration of the floor frame. Become. As a result, since the vibration energy is absorbed by the first torque box, the magnitude of the vibration transmitted to the side sill via the first torque box is kept below the magnitude of the vibration of the floor frame. It is done. Therefore, the vibration from the front wheel transmitted to the side sill can be suppressed as much as possible, and the vibration of the floor panel can be suppressed.

  Further, each of the left side and the right side of the vehicle includes a first torque box and a second torque box that is spaced apart from the first torque box on the rear side of the vehicle. At the time of a front collision, the first and second torque boxes serve as load paths, so that the load from the front collision can be properly transmitted from the floor frame to the side sill, and the rigidity against the front collision of the vehicle is properly secured. can do. Furthermore, since the load at the time of the frontal collision of the vehicle can be distributed by the first and second torque boxes and transmitted from the floor frame to the side sill, the sizes of the first and second torque boxes themselves are compared. Even if it is made small, the roll rigidity of the vehicle body can be ensured appropriately. Thereby, it can further suppress that the vibration from a front wheel is transmitted to a side sill from a floor frame.

  Further, since the plurality of torque boxes include the first torque box and the second torque box, the rigidity against the twist of the vehicle body, in particular, the twist in the roll direction of the vehicle body can be increased. It can be secured appropriately.

  In addition, since the second torque box is separated from the suspension cross member toward the rear side of the vehicle relative to the first torque box, vibration from the front wheels is hardly transmitted. In other words, since the vibration itself transmitted to the side sill via the second torque box is small, even if the ridge line of the second torque box and the ridge line of the floor frame coincide with each other, the vibration of the floor panel is not greatly affected. There is no. On the other hand, if the ridge line of the second torque box matches the ridge line of the floor frame, the rigidity of the second torque box can be increased, and the load path performance and the roll rigidity of the vehicle body can be improved.

  Therefore, the vibration of the floor panel caused by the vibration from the front wheels being transmitted to the torque box can be suppressed as much as possible without reducing the roll rigidity of the vehicle body.

  In the lower vehicle body structure of the vehicle, the protruding amount of the first torque box with respect to the floor panel at a position where the first torque box is in contact with the floor frame is the floor frame of the second torque box. It is desirable that the amount of protrusion of the second torque box with respect to the floor panel is smaller than the amount of protrusion of the second torque box.

  With this configuration, the ridgeline of the floor frame and the ridgeline of the first torque box at the contact position with the floor frame of the first torque box are more inconsistent than the second torque box. The torque box is more easily deformed with respect to the vibration of the floor frame, and vibration energy is easily absorbed. Thereby, the magnitude | size of the vibration transmitted to a side sill via a 1st torque box can be made as small as possible. As a result, the vibration of the floor panel can be further effectively suppressed.

  In the lower vehicle body structure of the vehicle, the protruding amount of the first torque box with respect to the floor panel is in contact with the floor frame of the second torque box over the entire longitudinal direction of the first torque box. It is desirable that the amount of protrusion of the second torque box with respect to the floor panel in the contact position is smaller.

  With this configuration, the amount of protrusion of the first torque box with respect to the floor panel can be made as small as possible over the entire longitudinal direction of the first torque box, so that the first torque box is transmitted to the side sill via the first torque box. The magnitude of the generated vibration can be made as small as possible. Thereby, the vibration of a floor panel can be suppressed more effectively.

  In one embodiment of the lower vehicle body structure of the vehicle, the lower wall portion of the first torque box is in contact with the outer side wall of the floor frame in the vehicle width direction.

  Moreover, in the case of the said one Embodiment, it is good also as a structure that the lower wall part of a said 1st torque box is joined to the side wall of the outer side of the vehicle width direction of the said floor frame.

  According to this configuration, it is possible to prevent the vibration of the lower wall portion of the floor frame from being transmitted to the first torque box, and to reduce the vibration transmitted from the floor frame to the first torque box. That is, the ridgeline of the first torque box is directly connected to the ridgeline of the floor frame because the lower wall portion of the first torque box is in contact with or joined to the outer side wall of the floor frame in the vehicle width direction. No structure. Thereby, the vibration of the floor frame makes it easy for the first torque box to be deformed, the energy of the vibration is easily absorbed, and the magnitude of the vibration transmitted to the side sill through the first torque box can be made. As small as possible. As a result, the vibration of the floor panel can be more effectively suppressed.

  In another embodiment of the lower vehicle body structure of the vehicle, the lower wall portion of the second torque box is not in contact with the outer side wall of the floor frame in the vehicle width direction, and is not in contact with the lower wall portion of the floor frame. It is joined.

  As described above, the portion of the floor frame at the same vehicle front-rear position as the connection portion between the floor frame and the second torque box is compared with the connection portion between the floor frame and the first torque box. Since it is away from the member, the vibration from the front wheels input to the second torque box is relatively small. For this reason, even if the lower wall portion of the second torque box is connected to the lower wall portion of the floor frame without being brought into contact with the outer side wall of the floor frame, the second torque box The vibration transmitted to the side sill is small. On the other hand, by connecting the lower wall portion of the second torque box to the lower wall portion of the floor frame, the ridge line of the second torque box can be made to coincide with the ridge line of the floor frame. The load path for the collision load can be appropriately configured. As a result, the rigidity with respect to the front collision of the vehicle can be ensured more appropriately.

  In the lower vehicle body structure of the vehicle, the maximum value of the area of the closed cross section constituted by the first torque box and the floor panel is the closed cross section constituted by the second torque box and the floor panel. It is desirable that it be larger than the maximum value of the area.

  That is, from the viewpoint of improving the roll rigidity of the vehicle body, it is desirable that the area of the closed cross section constituted by the first torque box, which is a torque box relatively close to the suspension cross member, and the floor panel is as large as possible. . Therefore, the maximum value of the area of the closed cross section constituted by the first torque box and the floor panel is within a range in which vibration from the front wheels can be suppressed from being transmitted to the floor panel via the torque box. It is made larger than the maximum value of the area of the closed cross section constituted by the second torque box and the floor panel. Thereby, the roll rigidity of the vehicle body and the like can be further improved while suppressing the vibration from the front wheels from being transmitted to the floor panel via the first torque box.

  In the lower vehicle body structure of the vehicle, the floor panel has a floor panel body that extends substantially horizontally so as to form a vehicle compartment floor of the vehicle, and an end of the floor panel body on the vehicle front side toward the vehicle front side. An end of the toe board on the vehicle rear side is overlapped and joined in the vertical direction to an end of the floor panel body on the vehicle front side, and the end of the second torque box on the vehicle front side It is desirable that the end portion is overlapped and joined in the vertical direction to the joint portion between the floor panel body and the toe board.

  According to this configuration, it is possible to improve the bonding strength between the floor panel body and the toe board using the second torque box, and to improve the roll rigidity of the vehicle body.

  Further, the separation distance in the vehicle front-rear direction between the first torque box and the second torque box can be made as large as possible. As a result, the second torque box can be disposed as far as possible from the coupling portion between the suspension cross member and the floor frame, so that it is difficult to transmit vibration from the front wheels to the second torque box. Can do. Thereby, it can suppress more effectively that the vibration from a front wheel is transmitted to a floor panel.

  As described above, according to the lower body structure of the vehicle according to the present invention, the protrusion amount of the first torque box with respect to the floor panel is the same in the vehicle front-rear position as the connecting portion between the floor frame and the first torque box. Since it is smaller than the protrusion amount of the floor frame with respect to the floor panel, the magnitude of vibration transmitted to the side sill via the first torque box can be suppressed to be equal to or less than the magnitude of vibration of the floor frame. Thereby, it is suppressed that the vibration from the front wheel is transmitted to the side sill, and the vibration of the floor panel is suppressed. Further, the roll rigidity of the vehicle body can be appropriately ensured by the first and second torque boxes. Therefore, the vibration of the floor panel caused by the vibration from the front wheels being transmitted to the side sill via the torque box can be suppressed as much as possible without reducing the roll rigidity of the vehicle body.

It is the perspective view seen from the vehicle left side and the lower side which shows the front part of the vehicle to which the lower vehicle body structure which concerns on embodiment of this invention is applied. It is the bottom view which looked at the circumference with the left floor frame in the above-mentioned lower body structure from the lower side. It is sectional drawing cut | disconnected by the III-III line | wire of FIG. It is sectional drawing cut | disconnected by the IV-IV line of FIG. It is sectional drawing cut | disconnected by the VV line | wire of FIG. It is sectional drawing cut | disconnected by the VI-VI line of FIG. It is sectional drawing cut | disconnected by the VII-VII line of FIG.

  Hereinafter, Embodiment 1 of the present invention will be described in detail with reference to the drawings. In the following description, the front, rear, left, right, upper and lower of the vehicle 1 are simply referred to as front, rear, left, right, upper and lower, respectively.

  FIG. 1 shows a front portion of a vehicle 1 to which a lower vehicle body structure according to Embodiment 1 of the present invention is applied. An engine room 2 for disposing an engine (not shown) for driving a front wheel (not shown) of the vehicle 1 and a transmission (not shown) is provided at the front portion of the vehicle 1. The engine is placed horizontally in the engine room 2, and the transmission is disposed on the left side of the engine unit.

  A pair of left and right front side frames 3 are disposed at both ends in the vehicle width direction of the engine room 2 so as to extend in the front-rear direction. The engine is disposed between the left and right front side frames 3. The rear portion of each front side frame 3 has a kick portion 3a whose height gradually decreases toward the rear side (in FIG. 1, the kick portion 3a of the right side frame 3 overlaps a suspension cross member 8 described later. The dash panel 4 that partitions the engine room 2 and the vehicle compartment is provided at the front and rear positions corresponding to the kick portion 3a. A floor frame 21 described later is joined to the rear end of each front side frame 3.

  Each front side frame 3 is formed with a flange 3b, and a rear end portion of the crash can 5 whose front end portion is connected to the bumper beam 6 is fastened to each flange 3b. The front end of the crash can 5 is connected by a bumper beam 6 extending in the vehicle width direction.

  A pair of left and right front wheel suspension arms 7 for supporting the left and right front wheels respectively at the front and rear positions of the front side of the vehicle 1 below the front side frames 3 and substantially the same as the kick parts 3a of the front side frame 3 A suspension cross member 8 (hereinafter referred to as a suspension cross 8) that extends in the vehicle width direction and supports each suspension arm 7 is disposed.

  The suspension cross 8 has an X-shape when viewed from the bottom, and the rear end portions of the left and right suspension arms 7 are attached and supported to the left rear end portion and the right rear end portion of the suspension cross 8, respectively. As a result, the front wheels are supported by the suspension cross 8 via the suspension arms 7. At the left front end and the right front end of the suspension cross 8, there is an upper extending portion 8a extending outward and upward in the vehicle width direction (in FIG. 1, the right upper extending portion 8a is connected to the right suspension arm 7). The left and right upper extending portions 8a are fixed to the lower surfaces of the left and right front side frames 3, respectively. Thereby, the suspension cross 8 and the left and right front side frames 3 are connected.

  From the left front end portion and the right front end portion of the suspension cloth 8, forward extending portions 9 extend toward the front side. Inner side surfaces in the vehicle width direction at front end portions of the left and right front extending portions 9 are connected by a front cross member 10 extending in the vehicle width direction. Further, a stiffener 11 for protecting pedestrians is fixed to the front end of each front extending portion 9 via a coupling member 15 so as to protrude forward. Further, the front end portions of the left and right front extending portions 9 and the front end portions of the left and right front side frames 3 are connected via a rubber mount extending vertically.

  Each front wheel suspension arm 7 is curved so as to be positioned on the outer side in the vehicle width direction toward the front side, and a wheel hub 51 is provided at the front end of each front wheel suspension arm 7 and on the outer end in the vehicle width direction. The hub carriers 50 are coupled to each other. The left and right front wheels are connected to the wheel hub 51 via hub bolts.

  The left and right hub carriers 50 are coupled to the lower ends of the rods 13a of the left and right shock absorbers 13, respectively. The left and right suspension towers 14 (on the left side in FIG. Only the suspension tower 14 is shown). The suspension tower 13 cooperates with the wheel house panel to form a wheel house in which the front wheel is disposed. The left and right suspension towers 14 are respectively fixed to the left and right front side frames 3, and the upper end portions of the left and right suspension towers 14 are disposed on the upper side of the left and right front side frames 5. 1 shows only the left apron member 16). The rear end portions of the left and right apron members 16 are joined to the upper end portions of the left and right hinge pillars 80, respectively. As will be described in detail later, the lower ends of the left and right hinge pillars 80 are respectively joined to left and right side sills 22 described later.

  As described above, the dash panel 4 for partitioning the engine room 2 and the vehicle compartment is provided at the front and rear positions corresponding to the kick portions 3a of the left and right front side frames 3. The dash panel 4 extends over the entire vehicle width direction of the vehicle 1. The dash panel 4 is joined to the left and right front side frames 3. In each part of the dash panel 4 on the left side and the right side of the front side frame 3, left and right toe boards 32 constituting the floor panel 30 are disposed at the lower end of the part.

  The floor panel 30 is a pair of left and right floor panel bodies 31 that extend substantially horizontally and are spaced apart in the vehicle width direction so as to form a passenger compartment floor of the vehicle 1, and from the front side end of the floor panel body 31 toward the front side. A pair of left and right toe boards 32 extending so as to incline upward, and an upper end portion of the toe board 32 is joined to a lower end portion of the dash panel 4.

  The left and right floor panel main bodies 31 and the left and right toe boards 32 are joined to each other on the left side and the right side by welding. Specifically, as shown in FIG. 7, the rear end of the toe board 32 is overlapped below the front end of the floor panel main body 31, and the front end of the floor panel main body 31 and the rear end of the toe board 32 are overlapped. The parts are overlapped and joined in the vertical direction by welding. The left and right toe boards 32 and the dash panel 4 are joined together by welding.

  The end portions of the floor panel 30 on the inner side in the vehicle width direction of the left and right toe boards 32 are connected by a front tunnel panel 41 constituting a tunnel portion through which the exhaust pipe of the engine passes. The upper end portion of the front tunnel panel 41 is joined to the lower end portion of the dash panel 4. Further, the inner edge portions in the vehicle width direction of the left and right floor panel main bodies 31 are connected to each other by a floor tunnel panel 42 constituting the tunnel portion. The front end of the floor tunnel panel 42 is joined to the rear end of the front tunnel panel 41. Thus, in the present embodiment, the floor panel 30 is configured by the left and right floor panel main bodies 31, the left and right toe boards 32, the front tunnel panel 41, and the floor tunnel panel 42. The left and right toe boards 32 and the front tunnel panel 41, the front tunnel panel 41 and the dash panel 4, the left and right floor panel bodies 31 and the floor tunnel panel 42, and the floor tunnel panel 42 and the front tunnel panel 41 are joined by welding. Yes.

  In the present embodiment, the floor panel 30 includes a pair of left and right floor frames 21 extending in the front-rear direction, and inner wall portions in the vehicle width direction of the left and right floor frames 21 (frame inner walls to be described later). A pair of left and right tunnel frames 23 joined to the portion 21a) and extending in the front-rear direction along the left and right ends of the floor tunnel panel 42, and a vehicle width wider than the pair of left and right floor frames in the floor panel 30. Torque box that is provided with a pair of left and right side sills 22 attached to an outer portion in the direction and a plurality of left and right side sills 22 and connects a pair of left and right floor frames 21 and a pair of left and right side sills 22 on the left and right sides, respectively. 60 is attached.

  Hereinafter, components of the lower vehicle body attached to the floor panel 30 (the floor panel main body 31 and the toe board 32) will be described in detail. In addition, since the lower vehicle body structure according to the present embodiment is configured symmetrically, in the following description, only components that are attached to the left side of the floor tunnel panel 42 in the floor panel 30 will be described. Detailed description of the components attached to the right side of the floor tunnel panel 42 in 30 will be omitted. Moreover, in the following description, about the member (floor frame 21 etc.) provided in both right and left, what is provided in the left side is pointed out.

  As shown in FIGS. 1 and 2, the floor frame 21 is joined to an intermediate portion in the vehicle width direction on the lower surface of the floor panel main body 31 and the toe board 32 by welding. As shown in FIGS. 1 and 4, the portion of the floor frame 21 joined to the toe board 32 is an inclined part 211 that extends while inclining upward toward the front side along the shape of the toe board 32. As shown in FIG. 2, the portion of the floor frame 21 joined to the floor panel body 31 is inclined horizontally toward the front and rear direction and slightly toward the left side (outside in the vehicle width direction) toward the rear side. It extends.

  The floor frame 21 has a U-shaped cross section that opens upward, and forms a closed cross-sectional space that extends in the front-rear direction in cooperation with the floor panel 30. The floor frame 21 has a frame inner side wall portion 21a located on the inner side (that is, the right side) in the vehicle width direction, and an outer side (that is, the left side) in the vehicle width direction so as to face the frame inner side wall portion 21a in the vehicle width direction. The frame outer side wall portion 21b is positioned, and a frame lower wall portion 21c that connects the lower end of the frame inner side wall portion 21a and the lower end of the frame outer side wall portion 21b.

  As shown in FIGS. 3, 5, and 6, frame welding allowances 212 d welded to the lower surface of the floor panel 30 are respectively formed from the upper end of the frame inner side wall 21 a and the upper end of the frame outer side wall 21 b. It extends. The right frame welding allowance 21d extends from the upper end of the frame inner side wall 21a toward the right, while the left frame welding allowance 21d extends from the upper end of the frame outer side wall 21b toward the left. ing.

  The amount of protrusion of the floor frame 21 with respect to the floor panel 30 is smaller on the front side than on the rear side. Specifically, as shown in FIG. 4, the protruding amount with respect to the toe board 32 at the part joined to the toe board 32 of the floor frame 21 is substantially the same as the front and rear position of the joined part between the floor panel body 31 and the toe board 32. The portion of the floor frame 21 that is joined to the floor panel body 31 is approximately the same as the first frame protrusion amount H1 that is the amount of protrusion with respect to the floor panel body 31, but the floor frame 21 in the portion corresponding to the inclined portion 211. The second frame protrusion amount H2, which is the protrusion amount of the toe board 32, is smaller than the first frame protrusion amount H1. As a result, the amount of protrusion of the floor frame 21 relative to the floor panel 30 (strictly toe board 32) at the same front-rear position as the connecting portion between the floor frame 21 and the first torque box 61 described later (the second frame protrusion amount H2). Is equivalent to the amount of protrusion of the floor frame 21 relative to the floor panel 30 (strictly speaking, the floor panel main body 31) at the same front-rear position as the connecting portion between the floor frame 21 and a second torque box 62 described later (first frame protrusion). Less than the amount H1).

  As shown in FIG. 3, the front end of the floor frame 21 is coupled to the left and rear portion of the suspension cross 8 via a suspension mount 18. More specifically, the front side end portion of the floor frame 21 is connected through the suspension mount 18 by the bolt 100 for attaching the front wheel suspension arm 7 to the suspension cross 8 at the same front and rear and left and right positions as the attachment portion of the suspension arm 7 in the suspension cross 8. Are coupled to the suspension cross 8.

  As shown in FIG. 3, the suspension mount 18 has a U-shaped cross section, and the lower portion of the floor frame 21 enters the inside of the suspension mount 18 from the U-shaped opening of the suspension mount 18. Specifically, the upper part of the inner side wall part 18a of the suspension mount 18 and the lower part of the frame inner side wall part 21a of the floor frame 21 overlap in the vehicle width direction, and the upper part of the outer side wall part 18b of the suspension mount 18 and the frame of the floor frame 21 The floor frame 21 is suspended from the suspension mount 18 so that the lower portion of the outer side wall portion 21b overlaps in the vehicle width direction, and the frame lower wall portion 21c of the floor frame 21 and the lower wall portion 18c of the suspension mount 18 are vertically separated. Is arranged against. The inner side wall portion 18a and the frame inner side wall portion 21a of the sus mount 18 and the outer side wall portion 18b and the frame outer side wall portion 21b of the sus mount 18 are joined by welding.

  A weld nut 70 extending in the vertical direction is welded to the upper surface of the lower wall portion 18 c of the suspension mount 18. A portion corresponding to the hole 70a of the weld nut 70 in the lower wall portion 18c of the suspension mount 18 has a suspension mount side hole portion 18d communicating with the hole portion 70a in the vertical direction. A frame side hole 21e through which the upper end of the weld nut 70 is inserted when the floor frame 21 is disposed in the suspension mount 18 is opened at the front end of the frame lower wall portion 21c of the floor frame 21. ing.

  On the other hand, the position corresponding to the suspension mount 18 in the suspension cross 8 is located at the rear end of the suspension arm 7 as shown in FIG. As shown in FIG. 3, a suspension bush 90 is provided at the rear end of the suspension arm 7. The suspension bush 90 includes an outer cylinder 91 fixed to the rear end of the suspension arm 7, an inner cylinder 92 disposed coaxially with the outer cylinder 91 inside the outer cylinder 91 and through which the bolt 100 is inserted, An elastic member 93 disposed between the outer cylinder 91 and the inner cylinder 92 is provided. As shown in FIG. 3, the inner cylinder 92 is fixed to the upper surface portion and the lower surface portion of the suspension cloth 8.

  A portion corresponding to the inside of the inner cylinder 92 in the suspension cloth 8 is formed with a suspension cross-side hole 8b communicating with the inside of the cylinder in the vertical direction.

  Actually, when the floor frame 21 is fixed to the suspension cloth 8, first, the suspension cloth 8 is placed below the suspension mount 18 so that the hole 70a of the weld nut 70 and the inside of the inner cylinder 92 communicate vertically. Deploy. Next, the bolt 100 is inserted from the lower side of the suspension cross 8 toward the weld nut 70 along the inner cylinder 92 and fastened to the weld nut 70. Accordingly, the floor frame 21 is coupled to the suspension cross 8 via the suspension mount 18, and the front end portions of the left and right floor frames 21 are coupled to each other by the suspension cross 8. At the same time, the suspension arm 7 is attached to the suspension cross 8.

  In the present embodiment, the suspension cross 8 and the floor frame 21 are connected not only by the suspension mount 18 but also by the gusset member 19. Specifically, as shown in FIG. 2, the front end portion of the gusset member 19 is fixed to the left side and the rear side portion of the suspension cross 8, that is, the portion in the vicinity of the attachment portion of the suspension arm 7 in the suspension cross 8 with the bolt 101. Has been. On the other hand, the rear end portion of the gusset member 19 extends from the coupling portion of the gusset member 19 and the suspension cloth 8 while being inclined slightly to the left side toward the rear side, and then to the frame lower wall portion 21c of the floor frame 21. It is fixed by bolts 102. The joining position of the rear side end portion of the gusset member 19 and the frame lower wall portion 21c is located at a position between a first torque box 61 and a second torque box 62 described later. That is, the gusset member 19 connects the suspension cloth 8 and the portion of the floor frame 21 between the first torque box 61 and the second torque box 62.

  As shown in FIG. 4, a weld nut 71 is provided in the suspension cloth 8 at a position where the bolt 101 is fastened in the suspension cloth 8, and the floor frame 21 is located at a position where the bolt 102 is tightened in the floor frame 21. A weld nut 72 is provided in the closed cross-sectional space.

  In the portion of the floor panel 30 where the floor frame 21 is attached, the surface of the floor panel 30 opposite to the floor frame 21 (that is, the upper surface) is to improve the rigidity of the floor frame 21 against a load such as a frontal collision of the vehicle. The reinforcing member 212 is provided.

  The tunnel frame 23 is joined to a portion slightly behind the rear end of the suspension cross 8 in the frame inner side wall portion 21a. The tunnel frame 23 extends from the joint portion with the frame inner side wall portion 21a to the right side in a curved manner and then extends in the front-rear direction along the left end portion of the floor tunnel panel 42.

  As shown in FIG. 6, the tunnel frame 23 has a U-shaped cross section that opens upward as in the floor frame 21, and forms a closed cross-section space in cooperation with the floor panel 30. Specifically, the curved portion of the tunnel frame 23 is joined to the toe board 32 and forms a closed cross-sectional space in cooperation with the toe board 32. On the other hand, in the portion extending along the floor tunnel panel 42 in the tunnel frame 23, the upper end portion of the right side wall portion is the floor tunnel panel 42 (strictly, the joint portion between the floor tunnel panel 42 and the floor panel body 31). (See FIG. 6) On the other hand, the upper end of the left side wall is joined to the floor panel body 31 to form a closed cross-section space in cooperation with the floor panel body 31.

  As shown in FIGS. 5 and 6, the side sill 22 forms a closed cross-sectional space extending in the front-rear direction. The side sill inner 221 disposed on the right side (inner side in the vehicle width direction) and the side sill inner 22 a And a side sill outer 222 coupled from the left side (the outside in the vehicle width direction).

  The side sill inner 221 has a U-shaped cross-section that opens to the left side. The inner side upper wall part 221a, the inner side lower wall part 221b vertically opposite to the inner side upper wall part 221a, and the inner side upper part It has an inner side wall portion 221c that connects the right end portion of the wall portion 221a and the right end portion in the vehicle width direction of the inner lower wall portion 221b. Inner side welding allowances 221d are respectively formed at the left ends of the inner side upper wall part 221a and the inner side lower wall part 221b, and the upper inner side welding allowance 221d is the left side of the inner side upper wall part 221a. The lower inner welding allowance 221d extends downward from the left end of the inner lower wall portion 221b. As shown in FIG. 5, the front side portion of the upper and lower inner side welding allowances 221d of the side sill inner 221 is joined to the right side surface of a hinge pillar inner panel 83 to be described later by welding.

  As shown in FIGS. 5 and 6, the inner side wall portion 221 c is joined to the left end portion (the outer end portion in the vehicle width direction) of the toe board 32 and the floor panel body 31 by welding. 22 is attached to the floor panel 30.

  As shown in FIGS. 5 and 6, the inner side lower wall portion 221 a is located above the frame lower wall portion 21 c of the floor frame 21 in a state where the inner side wall portion 221 c and the floor panel 30 are joined. It is like that.

  Further, as shown in FIG. 5, a first reinforcing member 84 for reinforcing the hinge pillar inner panel 81 is joined to the inner side upper wall portion 221a by welding.

  The side sill outer 222 has a U-shaped cross section that opens to the right, and includes an outer side upper wall portion 222a, an outer side lower wall portion 222b that is vertically opposed to the outer side upper wall portion 222a, and an outer side upper portion. The outer side wall part 222c which connects the left end part of the wall part 222a and the left end part of the outer side lower wall part 222b is provided. Outer side welding allowances 222d are respectively formed on the right end portions of the outer side upper wall portion 222a and the outer side lower wall portion 222b, and the upper outer side welding allowance 222d is the right end of the outer side upper wall portion 222a. The lower outer welding allowance 222d extends downward from the right end of the outer lower wall portion 222b. The front portion of the upper and lower outer side welding allowances 222d of the side sill outer 222 is joined to the left side surface of the hinge pillar inner panel 81 by welding as shown in FIG.

  As shown in FIGS. 5 and 6, a second reinforcing member 85 for reinforcing the hinge pillar inner panel 81 is welded to the upper portion of the outer side wall portion 222c. A hinge pillar reinforcement 83 (hereinafter referred to as a hinge pillar rain 83), which is a component of the hinge pillar 80, is welded to the left side surface. As shown in FIG. 5, the second reinforcing member 85 is bent rightward at the middle portion in the vertical direction, then bent upward along the hinge pillar inner panel 81, and bent upward. This portion is joined to the hinge pillar inner panel 81 by a bolt 103 as will be described later.

  As shown in FIGS. 5 and 6, the hinge pillar rain 83 is covered with a hinge pillar outer panel 82 that is a component of the hinge pillar 80 from the left side (that is, outside in the vehicle width direction). A lower end portion of the hinge pillar outer panel 82 is welded to a joint portion between the second reinforcing member 85 and the outer side wall portion 222c.

  As shown in FIG. 5, the lower part of the hinge pillar inner panel 81 is sandwiched in the vehicle width direction by the upper and lower inner side welding allowances 221d and the upper and lower outer side welding allowances 222d. The inner side welding allowance 221d and the outer side welding allowance 222d are joined to the portion 83 by welding, respectively. Thereby, the lower part of the hinge pillar inner panel 81 is reinforced by the front part of the side sill 22, specifically, by the same front and rear position part as the hinge pillar 80 (see FIG. 1).

  In addition, as shown in FIG. 5, the upper end of the first reinforcing member 84, the upper end of the second reinforcing member 85, and the hinge pillar inner panel 81 are overlapped in the vehicle width direction by bolts 103. They are joined together.

  As described above, the upper and lower inner side welding allowances 221d of the side sill inner 221 and the upper and lower outer side welding allowances 222d of the side sill outer 222 are located on the hinge pillar inner panel 83 at the same front-rear position as the hinge pillar inner panel 83. On the other hand, as shown in FIG. 6, the rear part of the hinge pillar inner panel 83 is joined by welding, and the upper inner side welding allowance 221d, the upper outer side welding allowance 222d, and the lower inner part, as shown in FIG. The side welding allowance 221d and the lower outer welding allowance 222d are overlapped with each other in the vehicle width direction and joined by welding.

  In the present embodiment, the plurality of torque boxes 60 are arranged at substantially the same front-rear position as the joint portion between the floor frame 21 and the tunnel frame 23 and extend in the vehicle width direction, and the first torque box 61 The second torque box 62 includes a second torque box 62 that is spaced rearward from the torque box 61 and extends in parallel with the first torque box 61. As shown in FIG. 2, the first and second torque boxes 61 and 62 connect the frame outer side wall portion 21 b of the floor frame 21 and the inner side wall portion 221 c of the side sill inner 221 in the vehicle width direction. It extends along the vehicle width direction.

  As shown in FIG. 7, the first torque box 61 has a U-shaped cross section that opens upward, and forms a closed cross-sectional space that extends in the vehicle width direction in cooperation with the toe board 32. The first torque box 61 is located on the first box side front wall portion 61a, on the rear side and obliquely below the first box side front wall portion 61a, and is opposed to the first box side front wall portion 61a. First box side rear wall portion 61b, a first box side lower wall portion 61c that connects a lower end portion of the first box side front wall portion 61a and a lower end portion of the first box side rear wall portion 61b. And have. A first box side welding allowance 61d welded to the lower surface of the floor panel 30 (strictly toe board 32) is provided at the upper end of the first box side front wall portion 61a and the first box side rear wall portion 61b. ing. The first box side welding allowance 61d on the front side extends from the upper end of the first box side front wall portion 61a to the front side, and the first box side welding allowance 61d on the rear side is the first box side rear wall portion 61b. It extends to the rear side from the upper end portion. The front and rear first box side welding allowances 61d are joined to the toe board 32 by welding. Although not shown in detail, the welding allowance is also applied to the left end and the right end of the first box side front wall 61a and the left end and the right end of the first box side rear wall 61b. The welding margin on each left side is joined to the frame outer side wall portion 21 b of the floor frame 21, while the welding margin on each right side is joined to the inner side wall portion 221 c of the side sill inner 221.

  The first box-side lower wall portion 61c of the first torque box 61 has a left end joined to the inner-side lower wall portion 221b of the side sill inner 221 by welding, and is floored from the joint portion with the inner-side lower wall portion 221b. To the frame 21, it extends straight to the right at substantially the same height as the inner side lower wall portion 221 b, and then comes into contact with the frame outer side wall portion 21 b of the floor frame 21. The first box joined to the frame lower wall portion 21c from the right end portion of the first box side lower wall portion 61c (that is, the contact portion between the first box side lower wall portion 61c and the frame outer side wall portion 21b). The side inner joint 61e extends. The first box side inner joint portion 61e extends downward from the right end portion of the first box side lower wall portion 61c along the frame outer side wall portion 21b, and is at substantially the same height position as the frame lower wall portion 21c. It extends to the right side (inward in the vehicle width direction) along the frame lower wall portion 21c. And the part extended along the frame lower wall part 21c in the 1st box side inner side junction part 61e is joined to this frame lower wall part 21c by welding. The first box-side lower wall portion 61c does not have to extend strictly straight to the right side, and the first box-side lower wall portion 61c may be uneven at an intermediate portion in the vehicle width direction. Good.

  The first box-side lower wall portion 61c extends straight from the joint portion with the inner-side lower wall portion 221b toward the floor frame 21 at substantially the same height as the inner-side lower wall portion 221b. The first box side lower wall portion 61c is positioned above the frame lower wall portion 21c. That is, the protrusion amount H3 (see FIG. 7) of the first torque box 61 with respect to the floor panel 30 (strictly, the toe board 32), specifically, the first torque box 61 is perpendicular to the extending direction of the toe board 32. The protruding amount H3 in the direction is the floor panel 30 of the floor frame 21 at the same front-rear position as the connecting portion between the floor frame 21 and the first torque box 61 over the entire longitudinal direction of the first torque box 61. Strictly speaking, it is smaller than the protruding amount (second frame protruding amount H2) with respect to the toe board 32). The protrusion amount H3 of the first torque box 61 with respect to the floor panel 30 does not include the protrusion amount with respect to the floor panel 30 at the first box side inner joint portion 61e.

  As shown in FIG. 7, the second torque box 62 has a U-shaped cross section that opens upward, and forms a closed cross-sectional space that extends in the vehicle width direction in cooperation with the floor panel body 31. . The second torque box 62 includes a second box side front wall portion 62a, a second box side rear wall portion 62b opposite to the second box side front wall portion 62a in the front-rear direction, and a second box side front wall portion. A second box side lower wall portion 62c that connects the lower end portion of 62a and the lower end portion of the second box side rear wall portion 62b is provided. A second box side welding allowance 62d welded to the lower surface of the floor panel 30 (strictly, the floor panel main body 31) is formed on the upper end portions of the second box side front wall portion 62a and the first box side rear wall portion 62b. Each is provided. The front second box side welding allowance 62d extends to the front side from the upper end of the second box side front wall 62a, and the rear second box side welding allowance 62d is the second box side rear wall 61b. It extends to the rear side from the upper end portion. Although not shown in detail, welding margins are also provided at the left and right end portions of the second box side front wall portion 62a and the left and right end portions of the second box side rear wall portion 62b. The welding allowance on the left side is joined to the frame outer side wall portion 21b of the floor frame 21, while the welding allowance on the right side is joined to the inner side wall portion 221c of the side sill inner 221.

  As shown in FIG. 7, the second box side welding allowance 62d on the front side is superposed on the joint portion between the floor panel body 31 and the toe board 32 from below, and is superposed and joined to the joint portion in the vertical direction by welding. Has been. That is, the front second box side welding allowance 62 d corresponding to the front end portion of the second torque box 62 is overlapped and joined to the joint portion between the floor panel body 31 and the toe board 32 in the vertical direction. As a result, the floor panel main body 31, the toe board 32, and the front second box side welding allowance 62d are joined in the up and down direction. The rear second box side welding allowance 62d is joined to the floor panel body 31 by welding.

  As long as the first torque box 61 and the second torque box 62 can be separated from each other in the front-rear direction, the second box-side welding allowance 62d on the rear side is a joint between the floor panel body 31 and the toe board 32. May be superposed and bonded together. However, as will be described later, the first torque box 61 and the second torque box 62 are separated as much as possible from the viewpoint of reducing vibration transmitted from the floor frame 21 to the second torque box 62. It is desirable that the second box side welding allowance 62d on the front side is overlapped and joined to the joint portion between the floor panel main body 31 and the toe board 32.

  As shown in FIG. 6, the second box side lower wall portion 62 c of the second torque box 62 has a left end joined to the inner side lower wall portion 221 b of the side sill inner 221 by welding, and the inner side lower wall portion. The portion extending from the joint portion with 221b is inclined downward toward the frame lower wall portion 21c of the floor frame 21. And the 2nd box side inner side junction part 62e provided in the right end part of the 2nd box side lower wall part 62c is joined to the flame | frame lower wall part 21c by welding. That is, the second box side lower wall portion 62c is joined to the frame lower wall portion 21c without contacting the frame outer side wall portion 21b.

  After the second box side lower wall portion 62c extends obliquely downward from the joint portion with the inner side lower wall portion 221b toward the frame lower wall portion 21c of the floor frame 21, the second box side inner joint portion 62e. , The amount of protrusion of the second torque box 62 with respect to the floor panel 30 (strictly, the floor panel body 31) is in the longitudinal direction of the second torque box 62. Throughout the entire projecting amount of the floor frame 21 with respect to the floor panel 30 (strictly speaking, the floor panel body 31) at the same front-rear position as the connecting portion between the floor frame 21 and the second torque box 61 (first frame projecting amount). H1) In addition, the protrusion amount with respect to the floor panel 30 of the 2nd torque box 62 does not include the protrusion amount with respect to the floor panel 30 in the part of the 2nd box side inner side junction part 62e.

  As described above, the first box-side lower wall portion 61c of the first torque box 61 extends straight to the right at substantially the same height as the inner-side lower wall portion 221b, while the second box of the second torque box 62 Since the side lower wall portion 62c extends from the joint portion with the inner side lower wall portion 221b so as to be inclined downward toward the frame lower wall portion 21c of the floor frame 21, as shown in FIG. 5, FIG. 6, and FIG. Further, the protrusion amount H3 (see FIG. 7) of the first torque box 61 with respect to the floor panel 30 (strictly, the toe board 32), specifically, the first torque box 61 is perpendicular to the extending direction of the toe board 32. The protruding amount H3 in the appropriate direction is set to the floor panel 30 (strictly speaking, the floor panel body 32) of the second torque box 62 over the entire longitudinal direction of the first torque box 61. Becomes the protruding amount less size that. More specifically, the protrusion amount H3 of the first torque box 61 with respect to the floor panel 30 is in contact with the side sill inner 61 of the second torque box 62 over the entire length of the first torque box 61. While the protrusion amount H4 (see FIG. 6) of the second torque box 62 with respect to the floor panel 30 at the contact position is approximately the same, the second torque box 62 at the contact position with the floor frame 21 is the same. The amount of protrusion of the second torque box 62 with respect to the floor panel 30 (approximately the same as the amount of protrusion of the first frame H1) is smaller.

  On the other hand, as shown in FIGS. 2 and 7, the first torque box 61 has a shorter length of the first torque box 61 than a shorter length of the second torque box 62. It is configured to be long. More specifically, the first torque box 61 has an average width between the length W1 in the short direction of the opening of the first torque box 61 and the length W2 in the short direction of the first box side lower wall portion 61c. Is configured to be larger than the average width of the length W3 in the short direction of the opening of the second torque box 62 and the length W4 in the short direction of the second box side lower wall portion 62c. . As a result, the maximum value of the area of the closed cross section formed by the first torque box 61 and the floor panel 30 (strictly, the toe board 32) is the second torque box 62 and the floor panel 30 (strictly, the floor panel 30). It is configured to be larger than the maximum value of the area of the closed cross section constituted by the panel body 31). That is, the length of the first torque box 61 in the short direction is such that the maximum value of the area of the closed cross section formed by the first torque box 61 and the floor panel 30 is the second torque box 62 and the floor panel. The width is set so as to be larger than the maximum value of the area of the closed cross section composed of 30. As will be described in detail later, if the area of the closed cross section constituted by the first torque box 61 and the floor panel 30 is too large, vibrations from the front wheels are likely to be transmitted to the floor panel 30, The area of the closed cross-section is increased within a range in which vibration from the front wheels can be suppressed from being transmitted to the floor panel 30 via the first torque box 61.

  Furthermore, in the present embodiment, the length of the first torque box 61 in the short direction (that is, the length W1 of the opening of the first torque box 61 in the short direction and the short length of the first box side lower wall portion 61c). The average length of the hand-direction length W2) is the average value of the area of the closed cross section formed by the first torque box 61 and the floor panel 30, and the second torque box 62 and the floor panel 30 The length is set to be larger than the average value of the area of the closed cross-section formed by

  In the present embodiment, the constituent members of the lower vehicle body attached to the left part of the floor panel 30 are configured as described above. The constituent members of the lower vehicle body attached to the right portion of the floor panel 30 are configured to be bilaterally symmetric with the constituent members of the lower vehicle body attached to the left portion of the floor panel 30 described above.

  Here, in a vehicle having a conventional lower body structure, when the vehicle travels, vibrations from the engine and vibrations from the left and right front wheels are transmitted to the floor panel 30 and the floor panel 30 may vibrate. . This is because the vibration of the front wheel is transmitted from the front wheel suspension arm 7 or the like to the floor frame 21 to vibrate the floor frame 21, and the torque box 60 vibrates due to the vibration of the floor frame 21. This is because the side sill 22 vibrates due to the vibration of the side sill and the vibration of the side sill 22 is transmitted to the floor panel 30.

  Conventionally, in order to increase the rigidity of the vehicle body, the amount of protrusion of the first torque box 61 with respect to the floor panel 30 is set at the same vehicle front-rear position as the connecting portion between the floor frame 21 and the first torque box 61. The ridgeline of the floor frame 21 and the ridgeline of the first torque box 61 were made to coincide with the amount of protrusion of the floor frame 21 with respect to the floor panel 30. However, if the ridge line of the floor frame 21 and the ridge line of the first torque box 61 coincide with each other, the rigidity of the first torque box 61 becomes too high, and the vibration from the frame lower wall portion 21c of the floor frame 21 is directly subjected to the side sill. Therefore, vibration from the front wheels is easily transmitted to the floor panel 30.

  The vibration of the floor panel 30 as described above causes unpleasantness to the vehicle occupant, and causes vibrations in the air in the vehicle interior of the vehicle to cause noise. Make the (Noise Vibration Harshness) problem noticeable.

  It is conceivable to reduce the vibration of the floor panel 30 by reducing the size of the torque box 60 and reducing the vibration transmitted to the side sill 22 through the torque box 60. However, if the size of the torque box 60 is reduced In addition, the roll rigidity of the vehicle body and the rigidity against the front collision may be reduced.

  Therefore, it is required to configure the torque box 60 so that the vibration from the front wheels can be suppressed to the floor panel 30 as much as possible without reducing the roll rigidity or the like of the vehicle body. .

  Therefore, in the present embodiment, the protrusion amount H3 of the first torque box 61 with respect to the floor panel 30 is set to the same level as the connecting portion between the floor frame 21 and the first torque box 61. It was made smaller than the amount of protrusion.

  Thereby, compared with the case where the ridgeline of the floor frame 21 and the ridgeline of the 1st torque box 61 correspond, the rigidity of the 1st torque box 61 becomes low. It becomes easy to deform by vibration. As a result, since the vibration energy is absorbed by the first torque box 61, the magnitude of the vibration transmitted to the side sill 22 via the first torque box 61 is the magnitude of the vibration of the floor frame 21. Or less. Therefore, vibration from the front wheels transmitted to the side sill 22 can be suppressed as much as possible, and thus vibration of the floor panel 30 can be suppressed.

  In addition, each of the left side and the right side of the vehicle includes a first torque box 61 and a second torque box 62 that is disposed rearwardly with respect to the first torque box 61. At the time of a frontal collision of the vehicle 1, the first and second torque boxes 61 and 62 serve as a load path so that the load caused by the frontal collision can be appropriately transmitted from the floor frame 21 to the side sill 22. It is possible to appropriately secure the rigidity against the front collision. Furthermore, since the load at the time of the frontal collision of the vehicle 1 can be distributed by the first and second torque boxes 61 and 62 and transmitted from the floor frame 21 to the side sill 22, the first and second torque boxes Even if the sizes of 61 and 62 themselves are relatively small, the rigidity of the vehicle 1 with respect to the front collision can be appropriately ensured. Thereby, it can further suppress that the vibration from the said front wheel is transmitted from the floor frame 21 to the side sill 22.

  Further, since the torque box 60 includes the first torque box 61 and the second torque box 62, the rigidity against the twist of the vehicle body, particularly the twist in the roll direction of the vehicle body can be increased, and the roll rigidity of the vehicle body can be increased. Can be secured appropriately.

  Further, since the second torque box 61 is separated from the suspension cloth 8 on the rear side of the first torque box 61, the vibration itself from the front wheels is difficult to be transmitted. That is, since the vibration itself transmitted to the side sill 22 through the second torque box 62 is small, the second box side lower wall portion 62c does not contact the frame outer side wall portion 21b as in the present embodiment. Even if the ridge line of the second torque box 62 and the ridge line of the floor frame 21 coincide with each other so as to be joined to the frame lower wall portion 21c, the vibration of the floor panel 30 is not significantly affected. On the other hand, since the ridge line of the second torque box 62 and the ridge line of the floor frame 21 coincide with each other, the rigidity of the second torque box 62 can be increased, and the load path performance and the roll rigidity of the vehicle body can be improved. Can be improved.

  In the present embodiment, since the second torque box 62 is spaced apart from the first torque box 61 on the rear side, the floor frame 21, the side sill 22, and the first torque box 61 are arranged. The second torque box 62 forms a frame. Thereby, the rigidity with respect to the twist of the vehicle body, particularly the twist in the left-right direction can be increased, and the roll rigidity of the vehicle body can be ensured appropriately.

  Therefore, the vibration of the floor panel 30 caused by the vibration from the front wheel being transmitted to the torque box 60 can be suppressed without reducing the roll rigidity or the like of the vehicle body.

  In the present embodiment, the first and second torque boxes 61 and 62 that connect the floor frame 21 and the side sill inner 221 in the vehicle width direction are arranged so as to extend straight along the vehicle width direction. Yes. Thereby, it is possible to make it difficult to displace the floor frame and the side sill with respect to torsion of the vehicle body, particularly torsion in the roll direction of the vehicle body, and it is possible to improve the roll rigidity of the vehicle body.

  Furthermore, in the present embodiment, the first torque box 61 is disposed at substantially the same front-rear position as the joint portion between the floor frame 21 and the tunnel frame 23. Therefore, at the front-rear position, the floor frame 21 is connected to the tunnel. The frame 23 and the first torque box 61 are sandwiched in the vehicle width direction. As a result, in the floor frame 21, the portion in the front-rear position substantially the same as the joint portion with the first torque box 61 is prevented from being twisted in the roll direction by the first torque box 61 and the tunnel frame 23. become. As a result, the roll rigidity of the vehicle body can be further improved.

  Further, in the present embodiment, the second box side welding allowance 62d on the front side of the second torque box 62 is overlapped and joined to the joining portion of the floor panel body 31 and the toe board 32 in the vertical direction. The first torque box 61 and the second torque box 62 can be appropriately separated in the front-rear direction. As a result, the second torque box 62 can be disposed as far as possible from the connecting portion between the suspension cross 8 and the floor frame 21 (strictly speaking, the floor frame 21). It can be made difficult to transmit to the second torque box 62. As a result, transmission of vibration from the front wheels to the floor panel 30 can be more effectively suppressed.

  Furthermore, since the floor panel main body 31, the toe board 32, and the second box side welding allowance 62d are joined, the floor panel main body 31, the toe board 32 and the second torque box 62 are used. The joint strength can be improved, and the roll rigidity of the vehicle body can be improved.

  Further, in the present embodiment, the maximum value of the area of the closed cross section constituted by the first torque box 61 and the floor panel 30 (strictly toe board 32) is the second torque box 62 and the floor panel 30 (strictly Is larger than the maximum value of the area of the closed cross section constituted by the floor panel main body 31), so that the vibration from the front wheel is prevented from being transmitted to the floor panel 30 via the first torque box 61. The rigidity of the first torque box 61 itself is improved while suppressing the vibration from the front wheel from being transmitted to the floor panel 30 via the first torque box 61. In addition, the roll rigidity of the vehicle body can be further improved.

  Therefore, in the present embodiment, a pair of left and right floor frames 21 extending in the front-rear direction and attached to the lower surface of the floor panel 30, and left and right extending in the vehicle front-rear direction and attached to the outer end of the floor panel 30 in the vehicle width direction. A pair of side sills 22; suspension suspension members 8 that connect the front ends of the left and right floor frames 21 and support the left and right front wheel suspension arms 7; and a plurality of left and right floor frames 21 The left and right side sills 22 are connected to each other on the left side and the right side, and a plurality of torque boxes 60 are connected to the first torque box 61 and the first torque box 61 on each of the left side and the right side. The second torque that is disposed away from the torque box 61 on the rear side of the vehicle. The floor frame 21 has a U-shaped cross section that opens upward, and forms a closed cross section in cooperation with the floor panel 30. The torque boxes 61 and 62 have a U-shaped cross section that opens upward in the vehicle longitudinal direction, and forms a closed cross section in cooperation with the floor panel 30, so that the floor panel 30 of the second torque box 62 The amount of protrusion relative to the floor frame 21 and the second torque box 62 is equal to or less than the amount of protrusion of the floor frame 21 relative to the floor panel 30 at the same vehicle front-rear position as the connecting portion between the floor frame 21 and the second torque box 62. The amount of protrusion with respect to the floor frame 21 is the same as the connecting portion between the floor frame 21 and the first torque box 61 at the vehicle front-rear position. Since it is smaller than the protruding amount with respect to the nell 30, the vibration of the floor panel 30 caused by the vibration of the front wheels being transmitted to the side sill 21 via the torque box 60 is suppressed as much as possible without reducing the roll rigidity of the vehicle body. To do.

  The present invention is not limited to the embodiment described above, and can be substituted without departing from the spirit of the claims.

  For example, in the above-described embodiment, the first box side inner joint portion 61e of the first torque box 61 is joined to the frame lower wall portion 21c of the floor frame 21, but not limited to this, the first box side The inner joint portion 61e may be joined to the outer side wall of the floor frame 21 in the vehicle width direction. In this case, it is not necessary to join the first box side inner joint portion 61e to the frame lower wall portion 21c. On the other hand, the floor frame 21 may not be in contact with both the outer side wall in the vehicle width direction and the frame lower wall portion 21c. In this case, the first torque box 61 is joined to the floor frame 21 at the inner end in the vehicle width direction of the first box side front wall portion 61a and the inner end in the vehicle width direction of the first box side rear wall portion 61b. Secured in the department.

  In the above-described embodiment, the second box-side lower wall portion 62c of the second torque box 62 does not contact the outer side wall in the vehicle width direction of the floor frame 21, and the second box-side inner joint portion 62e. However, the present invention is not limited to this, and the second box side lower wall portion 62c and the side wall on the outer side in the vehicle width direction of the floor frame 21 may be in contact with each other. Good. In this case, the second box side inner joint portion 62e may be joined to the outer side wall of the floor frame 21 in the vehicle width direction, or may be joined to the frame lower wall portion 21c.

  Furthermore, in the above-described embodiment, the torque box 60 is provided with the first torque box 61 and the second torque box 62 on each of the left side and the right side of the vehicle 1. Three or more torque boxes may be provided on each of the left side and the right side of the vehicle 1. However, since the weight of the vehicle body increases as the number of torque boxes is increased, from the viewpoint of reducing the weight of the entire vehicle body, the number of torque boxes is set to two on each of the left side and the right side of the vehicle 1. Is desirable.

  The above-described embodiments are merely examples, and the scope of the present invention should not be interpreted in a limited manner. The scope of the present invention is defined by the scope of the claims, and all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  INDUSTRIAL APPLICABILITY The present invention is useful as a lower body structure of a vehicle, and particularly for suppressing floor panel vibration caused by transmission of vibration from a front wheel to a torque box without reducing roll rigidity of the vehicle body. This is useful as a lower body structure of a vehicle.

DESCRIPTION OF SYMBOLS 1 Vehicle 7 Front-wheel suspension arm 8 Suspension cross member 21 Floor frame 21b Frame outer side wall part (outer wall part of a floor frame in the vehicle width direction)
21c Frame lower wall (lower wall of floor frame)
22 Side sill 30 Floor panel 31 Floor panel body 32 Toe board 60 Torque box 61 First torque box 61c First box side lower wall (lower wall of first torque box)
62 2nd torque box 62c 2nd box side lower wall part (lower wall part of 2nd torque box)
62d Second box side welding allowance (end of vehicle front side of second torque box)
H1 first frame protrusion amount (the protrusion amount of the floor frame with respect to the floor panel at the same vehicle front-rear position as the connecting portion between the floor frame and the second torque box)
H2 Second frame protrusion amount (the protrusion amount of the floor frame with respect to the floor panel at the same vehicle front-rear position as the connecting portion between the floor frame and the first torque box)
H3 Projection amount of the first torque box to the floor panel

Claims (8)

A lower body structure of a vehicle,
A pair of left and right floor frames extending in the vehicle longitudinal direction and attached to the lower surface of the floor panel;
A pair of left and right side sills extending in the vehicle front-rear direction and attached to the outer end of the floor panel in the vehicle width direction;
A suspension cross member for connecting the front end portions of the left and right floor frames and supporting the left and right front wheel suspension arms;
Provided in plural on the left side and the right side of the vehicle, and provided with a torque box for connecting the pair of left and right floor frames and the pair of left and right side sills respectively on the left side and the right side,
The plurality of torque boxes include a first torque box and a second torque box disposed on the vehicle rear side with respect to the first torque box on each of the left side and the right side of the vehicle. ,
The floor frame has a U-shaped cross section that opens upward in the vehicle width direction, and forms a closed cross section in cooperation with the floor panel,
The first and second torque boxes have a U-shaped cross section that opens upward in the vehicle longitudinal direction, and each of the first and second torque boxes forms a closed cross section in cooperation with the floor panel.
The amount of protrusion of the second torque box with respect to the floor panel is equal to or less than the amount of protrusion of the floor frame with respect to the floor panel at the same vehicle front-rear position as the connecting portion between the floor frame and the second torque box.
The amount of protrusion of the first torque box with respect to the floor panel is smaller than the amount of protrusion of the floor frame with respect to the floor panel at the same vehicle front-rear position as the connecting portion between the floor frame and the first torque box. A lower body structure of a vehicle characterized by The lower body structure of the vehicle according to claim 1,
The amount of protrusion of the first torque box with respect to the floor panel at the position of contact of the first torque box with the floor frame is the amount of protrusion of the second torque box with respect to the floor frame. A lower vehicle body structure for a vehicle, wherein the second torque box is smaller than a protruding amount of the second torque box with respect to the floor panel. In the lower vehicle body structure of the vehicle according to claim 1 or 2,
The amount of protrusion of the first torque box with respect to the floor panel is the second torque box in the contact position with the floor frame of the second torque box over the entire longitudinal direction of the first torque box. A lower vehicle body structure for a vehicle, wherein the protruding amount of the torque box relative to the floor panel is smaller. The lower body structure of the vehicle according to any one of claims 1 to 3,
A lower body structure of a vehicle, wherein a lower wall portion of the first torque box is in contact with an outer side wall of the floor frame in a vehicle width direction. The vehicle lower body structure according to claim 4,
A lower body structure of a vehicle, wherein a lower wall portion of the first torque box is joined to an outer side wall of the floor frame in the vehicle width direction. In the lower body structure of the vehicle according to any one of claims 1 to 5,
The lower body of the vehicle is characterized in that the lower wall portion of the second torque box is joined to the lower wall portion of the floor frame without contacting the outer side wall of the floor frame in the vehicle width direction. Construction. In the lower body structure of the vehicle according to any one of claims 1 to 6,
The maximum value of the area of the closed cross section constituted by the first torque box and the floor panel is larger than the maximum value of the area of the closed cross section constituted by the second torque box and the floor panel. A lower body structure of a vehicle characterized by In the lower vehicle body structure of the vehicle according to any one of claims 1 to 7,
The floor panel has a floor panel main body that extends substantially horizontally so as to constitute a passenger compartment floor of the vehicle, and a toe board that extends from the front end of the floor panel main body toward the front of the vehicle,
The vehicle rear side end of the toe board is overlapped and joined in the vertical direction to the vehicle front side end of the floor panel body,
A lower vehicle body structure for a vehicle, wherein an end portion of the second torque box on the vehicle front side is overlapped and joined in a vertical direction to a joint portion between the floor panel body and the toe board.

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